19,510 research outputs found
Forward-Security in Private-Key Cryptography
This paper provides a comprehensive treatment of forward-security in the context of sharedkey based cryptographic primitives, as a practical means to mitigate the damage caused by key-exposure. We provide definitions of security, practical proven-secure constructions, and applications for the main primitives in this area. We identify forward-secure pseudorandom bit generators as the central primitive, providing several constructions and then showing how forward-secure message authentication schemes and symmetric encryption schemes can be built based on standard schemes for these problems coupled with forward-secure pseudorandom bit generators. We then apply forward-secure message authentication schemes to the problem of maintaining secure access logs in the presence of break-ins
A fingerprint based crypto-biometric system for secure communication
To ensure the secure transmission of data, cryptography is treated as the
most effective solution. Cryptographic key is an important entity in this
procedure. In general, randomly generated cryptographic key (of 256 bits) is
difficult to remember. However, such a key needs to be stored in a protected
place or transported through a shared communication line which, in fact, poses
another threat to security. As an alternative, researchers advocate the
generation of cryptographic key using the biometric traits of both sender and
receiver during the sessions of communication, thus avoiding key storing and at
the same time without compromising the strength in security. Nevertheless, the
biometric-based cryptographic key generation possesses few concerns such as
privacy of biometrics, sharing of biometric data between both communicating
users (i.e., sender and receiver), and generating revocable key from
irrevocable biometric. This work addresses the above-mentioned concerns.
In this work, a framework for secure communication between two users using
fingerprint based crypto-biometric system has been proposed. For this,
Diffie-Hellman (DH) algorithm is used to generate public keys from private keys
of both sender and receiver which are shared and further used to produce a
symmetric cryptographic key at both ends. In this approach, revocable key for
symmetric cryptography is generated from irrevocable fingerprint. The biometric
data is neither stored nor shared which ensures the security of biometric data,
and perfect forward secrecy is achieved using session keys. This work also
ensures the long-term security of messages communicated between two users.
Based on the experimental evaluation over four datasets of FVC2002 and NIST
special database, the proposed framework is privacy-preserving and could be
utilized onto real access control systems.Comment: 29 single column pages, 8 figure
An Elliptic Curve-based Signcryption Scheme with Forward Secrecy
An elliptic curve-based signcryption scheme is introduced in this paper that
effectively combines the functionalities of digital signature and encryption,
and decreases the computational costs and communication overheads in comparison
with the traditional signature-then-encryption schemes. It simultaneously
provides the attributes of message confidentiality, authentication, integrity,
unforgeability, non-repudiation, public verifiability, and forward secrecy of
message confidentiality. Since it is based on elliptic curves and can use any
fast and secure symmetric algorithm for encrypting messages, it has great
advantages to be used for security establishments in store-and-forward
applications and when dealing with resource-constrained devices.Comment: 13 Pages, 5 Figures, 2 Table
Revisiting Deniability in Quantum Key Exchange via Covert Communication and Entanglement Distillation
We revisit the notion of deniability in quantum key exchange (QKE), a topic
that remains largely unexplored. In the only work on this subject by Donald
Beaver, it is argued that QKE is not necessarily deniable due to an
eavesdropping attack that limits key equivocation. We provide more insight into
the nature of this attack and how it extends to other constructions such as QKE
obtained from uncloneable encryption. We then adopt the framework for quantum
authenticated key exchange, developed by Mosca et al., and extend it to
introduce the notion of coercer-deniable QKE, formalized in terms of the
indistinguishability of real and fake coercer views. Next, we apply results
from a recent work by Arrazola and Scarani on covert quantum communication to
establish a connection between covert QKE and deniability. We propose DC-QKE, a
simple deniable covert QKE protocol, and prove its deniability via a reduction
to the security of covert QKE. Finally, we consider how entanglement
distillation can be used to enable information-theoretically deniable protocols
for QKE and tasks beyond key exchange.Comment: 16 pages, published in the proceedings of NordSec 201
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